Thanks for all the information.
After 4-5 years of living with my 99OBW's intermitent speedo, I finally used the advice from this thread and replaced the speedo head.
It only took about 30 minutes - I don't know why I waited so long.I guess one reason is I intend to drive the doors off this car and never sell it.
I do wonder what the actual mileage is on my car tho'. The odometer I just replced read 123,487mile, but I'm sure its a lot more than that
Is there any way to retrieve it from the ECU or ??
Thanks again to all the contributors here,
Paul